Loneliness is kinda drug addiction. Until you are aware of it, tough times look manageable. Once you are trapped into the real essence, easy times look haunting.
Imagine yourself in a crowd of thousands of fun loving people. You may feel enthralled once but you never know when suddenly your lost soul may ask you, "Who Am I ? Do I belong to this space ?".
When you read biography of successful folks or listen to fairy tales of adventurous people who chose to live life than survive, you surely get an idea on what's lacking in your conscience to handle life but still when the anxiety captures you, the goodie goodie inspiration takes a back seat and you alone come forward to face the real YOU.
You aren't alone. You have people around but still, you can't abstain yourself from overcoming the self-trauma. When you feel associated to the surroundings, loneliness feels good because you have something in your mind to hook yourself to. When you feel detached to your own self, loneliness becomes acidic. You can't stop crying, you can't stop going irrational, you can't stop going nuts. You just feel NO ONE.
I'm the NO ONE to my self at times !